Unreal Engine Issues
Unreal Engine Issues
With Ray Tracing Enabled And The RenderDoc Plugin Enabled Shadows Don't Render Correctly On Reflective Materials
UE - Graphics Features - Lumen - Jan 23, 2020When the RenderDoc plugin is installed with raytracing enabled shadows don't render correctly. Found in 4.24.1 CL#10757647 Reproduced in 4.23.1 CL#9631420, 4.25 Main CL#11087956 ...
Groom Assets do not cast shadows when the shadow casting light is close to the groom and virtual shadow maps are in use
UE - Graphics Features - Mar 19, 2024When a shadow casting light is closer to the groom than some proportional amount the groom is away from the shadow catcher, the groom's shadow will disappear. This only occurs using VSMs. Raytraced ...
Area scattering defaults to 0.01 spacing when input is invalid
TM - Tools - Dec 18, 2025If the user provides an invalid input for Area spacing (for example, using the hotkey 'R' to check the raytraced image), the spacing defaults to a value of 0.01m. Depending on the size of the Area s ...
Disabled Skeletal Mesh Sections cause Shadow Ray Tracing Flicker
UE - Rendering - Graphics Features - Ray Tracing - Dec 12, 2025If a skeletal mesh has a section disabled the ray traced shadow will flicker when the camera or itself moves. Previously in 5.6.0 no raytraced shadow would appear if a section was disabled. This wa ...
Morph target is not applied on the first frame in Level Sequence
UE - Anim - Rigging - Dec 4, 2025When a skeletal mesh with morph targets spawns in the sequence, the morph is not reflected in the first frame. In the ProcessStage_SkinCache call of SkeletalMesh, MorphVertexBuffer->SectionIds is ...
Crash occurs loading a sublevel containing landscape with ray tracing enabled
UE - LD & Modeling - Terrain - Landscape - May 13, 2020In raytracing enabled, When loading a sublevel containing landscape with LoadStreamLevel function following error is shown. Assertion failed: Pair != nullptr [Link Removed] [Line: 584] Licensee re ...
GetStaticRayTracingGeometries doesn't check if mesh has ray tracing disabled
UE - Rendering - Graphics Features - Ray Tracing - Nov 12, 2025An ensure is hit for static raytracing geometry because skeletal mesh assets that had ray tracing disabled were not handled in: FSkeletalMeshSceneProxy::GetStaticRayTracingGeometries The concurrent ...
Crash when a Deferred Decal (Translucent) base material has a Nanite Override (Masked Surface) Material and the mesh has Nanite + Ray Tracing enabled.
UE - Graphics Features - Ray Tracing - Aug 14, 2025A crash occurs when Nanite override material instance is used in a project with Ray tracing enabled where: 1 The Material assigned to the static mesh uses Deferred Decal / Translucent and the Nani ...
Point lights affect indirect lighting on RTGI much less than other types of lights
UE - Graphics Features - Lumen - Aug 4, 2020Only point lights affect indirect lighting on RTGI much less than other types of lights.[Link Removed] Indirect lighting of baked lightmaps look much stronger than RTGI.[Link Removed] Apparently, ...
Translucent materials in the PostMotionBlur pass can cause a flickering viewport artefact when using TAA
UE - Rendering - Graphics Features - Feb 5, 2025There appears to be a bug relating to rendering multiple windows that can trigger under unknown circumstances. It has been reported on rectangle lights in the forums and on PostMotionBlur materials ...